1. Field of the Invention
The present invention relates to alkali metal water-activated battery systems, to methods for making and operating the instant battery systems, and to cathodes and methods for producing a cathode therefor
2. Description of Related Art
Global issues are increasing the need for and expanding the role of underwater devices to monitor, survey, and explore oceans, harbors and coastal water systems. Underwater deployments and subsea applications abound. Examples include i) oil and gas companies evaluating the viability of an offshore oil field, or constructing, maintaining and operating offshore rigs, or responding to a catastrophic event (such as an oil spill); ii) sovereign nations conducting surveillance of their harbors and littoral zones, or performing underwater ship inspections or naval reconnaissance; and iii) the oceanographic community observing and collecting data on seismic activity and aquatic ecosystems. Underwater power sources, and in particular batteries, are needed to enable or otherwise support the ever-expanding role of these underwater applications.
Toward that end, prior work by the present applicants has enabled the practicality of alkali metal water-activated batteries, and in particular exceptionally lightweight lithium seawater batteries based on protected lithium electrodes capable of discharging over long periods of time with little or no corrosion. In accordance with applicant's prior work, these lithium seawater batteries have an open cell architecture wherein seawater serves as a conducting electrolyte between a protected lithium anode structure and a cathode open to the seawater environment. In some instances, seawater may also serve as the cathode depolarizer or the cathode may contain a solid phase electroactive material exemplified by transition metal halides, including cuprous chloride, silver chloride, and cuprous thiocyanate.
Non-limiting examples of open cell architecture lithium seawater batteries having a protected lithium electrode are described in Assignee's copending U.S. Patent Application Publication No.: 20110269007 to Visco et al., and Assignee's US patents, specifically U.S. Pat. Nos. 7,645,543; 7,824,806; and U.S. Pat. No. 7,282,295 to Visco et al., the entire disclosures of which are hereby incorporated by reference in their entirety. Moreover, the protected lithium electrodes, which provide a key component of said lithium seawater battery cells, are fully described in U.S. Pat. Nos. 7,645,543; 7,390,591; 7,824,806; 7,282,295, and U.S. Pat. No. 8,129,052 to Visco et al., which are also hereby incorporated by reference in their entirety.